Display device having touch sensing part

ABSTRACT

A display device includes: a first substrate including a first region, a third region spaced apart from and surrounding the first region, and a second region located between the first region and the third region; a second substrate opposite to the first substrate; a display element including a first electrode on the first substrate, a light emitting layer provided on the first electrode, and a second electrode provided on the light emitting layer; a touch sensing part disposed on the second substrate; and a sealing member provided on the third region of the first substrate, the sealing member joining the first substrate and the second substrate, wherein the second electrode overlaps with the touch sensing part when viewed on a plane, and an end of the second electrode is spaced apart from an end of the touch sensing part at a certain distance in the direction of the sealing member in the second region.

RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 15/604,180, filed on May 24, 2017, which claims priority toKorean Patent Application No. 10-2016-0072302 filed on Jun. 10, 2016 inthe Korean Intellectual Property Office, the entire disclosure of whichis incorporated by reference herein.

BACKGROUND 1. Field

An aspect of the present disclosure relates generally to displaydevices. More specifically, aspects of the present disclosure relate todisplay devices having reduced defects, and methods of theirmanufacture.

2. Description of the Related Art

Various display devices capable of displaying information have beendeveloped. Such display devices include a liquid crystal display device,a plasma display panel device, an electrophoretic display device, anorganic light emitting display device, and the like.

In general, manufacture of a display device involves a sealing processjoining two opposing substrates using a sealing member. In the sealingprocess, the sealing member may be heated by a laser beam and thencured. In this case, the laser beam may be transferred to a conductivelayer disposed in the vicinity of the sealing member through lightreflection, etc. However, when transferred to the conductive layer, thelaser beam may inadvertently be directed upon a display elementelectrically connected to the conductive layer, and therefore, a defectof the display element may be caused.

Accordingly, studies have been conducted to minimize defects in thedisplay device.

SUMMARY

Embodiments provide a display device and methods of its fabrication,which can improve the reliability of a display element.

According to an aspect of the present disclosure, there is provided adisplay device including: a first substrate including a first region, athird region spaced apart from and surrounding the first region, and asecond region located between the first region and the third region; asecond substrate opposite to the first substrate; a display elementincluding a first electrode provided on the first substrate, a lightemitting layer provided on the first electrode, and a second electrodeprovided on the light emitting layer; a touch sensing part disposed onthe second substrate; and a sealing member provided on the third regionof the first substrate, the sealing member joining the first substrateand the second substrate, wherein the second electrode overlaps with thetouch sensing part when viewed on a plane, and an end of the secondelectrode is spaced apart from an end of the touch sensing part at acertain distance in the direction of the sealing member in the secondregion.

The end of the second electrode may be disposed closer to the firstregion of the first substrate than the end of the touch sensing part.

The second electrode may be disposed on the first region and the secondregion, and may not overlap the sealing member.

The touch sensing part may be disposed in the first region and thesecond region, and may not overlap with the sealing member.

The second region may include a non-overlapping portion at which thesecond electrode and the touch sensing part do not overlap each other.

The width of the non-overlapping portion may be 80 μm or more.

The end of the second electrode may be disposed closer to the sealingmember than the end of the touch sensing part.

The second electrode may be disposed at portions of the first region,the second region, and the third region, and partially overlap with thesealing member in the third region when viewed on a plane.

The end of the second electrode may extend to a lower surface of thesealing member.

The touch sensing part may include touch sensing electrodes that areprovided on the second substrate and sense a touch, and connection linesconnected to the touch sensing electrodes.

The touch sensing electrodes may be disposed in a region correspondingto the first region of the first substrate on the second substrate, andthe connection lines may be disposed in a region corresponding to anyone of the second and third regions of the first substrate on the secondsubstrate.

The display device may further include a protective film provided on thetouch sensing part.

The first substrate may further include at least one thin filmtransistor connected to the display element to drive the displayelement.

The thin film transistor may include an active pattern provided on thefirst substrate; a gate electrode provided on the active pattern with agate insulating layer interposed therebetween; and source and drainelectrodes each connected to the active pattern. Any one of the sourceand drain electrodes may be electrically connected to the firstelectrode.

According to an aspect of the present disclosure, there is provided adisplay device including: a first substrate including a first region inwhich an image is displayed, a second region provided at the peripheryof the first region, and a third region provided at the periphery of thesecond region; a second substrate provided on the first substrate; aplurality of pixels displaying the image, the plurality of pixels eachincluding at least one thin film transistor and a light emitting deviceconnected to the thin film transistor; a touch sensing part provided onthe second substrate; and a sealing member provided in the third region,the sealing member joining the first substrate and the second substrate,wherein the light emitting device includes a first electrode provided onthe first substrate, a light emitting layer provided on the firstelectrode, and a second electrode provided on the light emitting layer,wherein the second electrode overlaps with the touch sensing part whenviewed on a plane, and an end of the second electrode is spaced apartfrom an end of the touch sensing part at a certain distance in thedirection of the sealing member in the second region.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will now be described more fully hereinafter withreference to the accompanying drawings; however, they may be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the example embodiments to those skilled in the art.

In the drawing figures, dimensions may be exaggerated for clarity ofillustration. It will be understood that when an element is referred toas being “between” two elements, it can be the only element between thetwo elements, or one or more intervening elements may also be present.Like reference numerals refer to like elements throughout. The variousfigures are not necessarily to scale.

FIG. 1 is a plan view schematically illustrating a display deviceaccording to a first embodiment of the present disclosure.

FIG. 2 is a sectional view taken along line I-I′ of FIG. 1.

FIG. 3 is a plan view conceptually illustrating a portion correspondingto section P1 of FIG. 1, which illustrates an arrangement relationshipamong a sealing member, a touch sensing part, and a second electrode.

FIG. 4 is a sectional view taken along line II-II′ of FIG. 1.

FIG. 5 is a plan view illustrating the touch sensing part of the displaydevice of FIG. 3.

FIG. 6 is a circuit diagram corresponding to a pixel of the displaydevice shown in FIG. 1.

FIG. 7 is a plan view corresponding to the pixel of FIG. 6.

FIG. 8 is a sectional view taken along line III-III′ of FIG. 7.

FIG. 9 is a graph illustrating changes in temperature of sealingmembers, second electrodes, and pixels due to irradiation of a laserbeam, for both an existing display device and a display device accordingto the first embodiment of the present disclosure.

FIG. 10 is an enlarged graph of a portion corresponding to section P2 ofFIG. 9.

FIGS. 11 to 14 are sectional views sequentially illustrating afabrication method for the display device of FIG. 4.

FIG. 15 is a sectional view illustrating a display device according to asecond embodiment of the present disclosure.

FIG. 16 is a sectional view illustrating a display device according to athird embodiment of the present disclosure.

DETAILED DESCRIPTION

The present disclosure may apply various changes and different shapes,and therefore only illustrates particular examples. However, theexamples are not limited to these certain shapes or configurations. Anyother shapes, materials, or the like are contemplated.

Like numbers refer to like elements throughout. In the drawings, thethickness of certain lines, layers, components, elements or features maybe exaggerated for clarity. It will be understood that, although theterms “first”, “second”, etc. may be used herein to describe variouselements, these elements should not be limited by these terms. Theseterms are only used to distinguish one element from another element.Thus, a “first” element discussed below could also be termed a “second”element without departing from the teachings of the present disclosure.As used herein, the singular forms are intended to include the pluralforms as well, unless the context clearly indicates otherwise.

It will be further understood that the terms “includes” and/or“including”, when used in this specification, specify the presence ofstated features, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence and/or addition of one ormore other features, integers, steps, operations, elements, components,and/or groups thereof. Further, an expression that an element such as alayer, region, substrate or plate is placed “on” or “above” anotherelement indicates not only a case where the element is placed “directlyon” or “just above” the other element but also a case where a furtherelement is interposed between the element and the other element. On thecontrary, an expression that an element such as a layer, region,substrate or plate is placed “beneath” or “below” another elementindicates not only a case where the element is placed “directly beneath”or “just below” the other element but also a case where a furtherelement is interposed between the element and the other element. Allnumerical values are approximate, and may vary. All examples of specificmaterials and compositions are to be taken as nonlimiting and exemplaryonly. Other suitable materials and compositions may be used instead.

Hereinafter, exemplary embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is a plan view schematically illustrating a display deviceaccording to a first embodiment of the present disclosure. FIG. 2 is asectional view taken along line I-I′ of FIG. 1.

Referring to FIGS. 1 and 2, the display device according to the firstembodiment of the present disclosure includes first to third regions 100a to 100 c.

The first region 100 a is a display region that includes a plurality ofpixels PXL to display an image. The image may include arbitrary visualinformation, e.g., text, video, pictures, two-dimensional orthree-dimensional images, and the like. The first region 100 a islocated at a central portion of the display device, and has a relativelylarge area as compared with the second region 100 b and the third region100 c.

The second region 100 b is a region in which lines for supplying anelectrical signal to the pixels PXL are arranged, and may be disposedbetween the first region 100 a and the third region 100 c.

The third region 100 c may be a cell sealing region in which a sealingmember 300 for sealing the plurality of pixels PXL provided in the firstregion 100 a is disposed. The third region 100 c may be spaced apartfrom the first region 100 a at a certain distance. The third region 100c may entirely surround the first region 100 a. Here, the second region100 b and the third region 100 c may be non-display regions in which theimage is not displayed.

In addition, the display device includes a first substrate 100, a secondsubstrate 200, an encapsulation layer 400 provided between the firstsubstrate 100 and the second substrate 200, and the sealing member 300.

The first substrate 100 and the second substrate 200 may be provided invarious shapes.

In an embodiment of the present disclosure, the second substrate 200 maybe provided to have a smaller area than the first substrate 100, but thepresent disclosure is not limited thereto. For example, the secondsubstrate 200 may be provided to have the same area as the firstsubstrate 100.

The first substrate 100 is positioned opposite to the second substrate200, and displays an image.

The first substrate 100 includes the pixels PXL provided thereon, andthe encapsulation layer 400 covering the pixels PXL.

The first substrate 100 may be made of an insulating material havingflexibility. The first substrate 100 may be made of various materials,e.g., glass, polymer metal, and the like. Particularly, the firstsubstrate 100 may be an insulating substrate made of a polymer organicmaterial. The material of the insulating substrate, including thepolymer organic material, includes polystyrene, polyvinyl alcohol,polymethyl methacrylate, polyethersulfone, polyacrylate, polyetherimide,polyethylene naphthalate, polyethylene terephthalate, polyphenylenesulfide, polyarylate, polyimide, polycarbonate, triacetate cellulose,cellulose acetate propionate, and the like. However, the materialconstituting the first substrate 100 is not limited thereto. Forexample, the first substrate 100 may be made of fiber glass reinforcedplastic (FRP).

Each pixel PXL is provided on the first region 100 a of the firstsubstrate 100. The pixel PXL is a minimum unit for displaying an image,and may be provided in plural numbers. The pixel PXL may include anorganic light emitting element that emits white light and/or coloredlight. The pixel PXL may emit light of any one color among red, green,and blue, but the present disclosure is not limited thereto. Forexample, the pixel PXL may emit light of a color such as cyan, magenta,or yellow. Any color or colors are contemplated.

The encapsulation layer 400 is provided on the first substrate 100 tocover the pixels PXL. The encapsulation layer 400 may be formed in asingle layer, but may also be formed in multiple layers.

The second substrate 200 includes a touch sensing part 210 providedthereon, and a protective film 220 provided over the touch sensing part210.

The second substrate 200 is provided corresponding to the shape of thefirst substrate 100. The second substrate 200 may have a shapeapproximately similar to that of the first substrate 100.

The touch sensing part 210 is disposed on the second substrate 200 torecognize a touch event to the display device through a user's hand orseparate input means. The touch sensing part 210 includes sensingelectrodes to sense a touch and/or a pressure, and the particular typeof touch sensing part 210 is not limited. For example, the touch sensingpart may be implemented as capacitive type sensors, pressure resistivetype sensors, and the like. The capacitive type sensor can be a mutualcapacitance type sensor in which a change in capacitance generated by aninteraction between two sensing electrodes is sensed, or can be aself-capacitance type sensor in which a change in capacitance of asensing electrode itself is sensed.

The protective film 220 is disposed over the touch sensing part 210 toplanarize step differences in elevation of the touch sensing part 210disposed thereunder. Also, the protective film 220 prevents oxygen andmoisture from being introduced into the touch sensing part 210 from theoutside. The protective film 220 may be configured in the form of a filmin which an inorganic material having a single- or multi-layeredstructure is coated on an organic material, but the present disclosureis not limited thereto.

FIG. 3 is a plan view conceptually illustrating a portion correspondingto section P1 of FIG. 1, which illustrates an arrangement relationshipamong the sealing member, the touch sensing part, and a secondelectrode. FIG. 4 is a sectional view taken along line II-II′ of FIG. 1.

Referring to FIGS. 1, 3, and 4, the display device according to thefirst embodiment of the present disclosure includes the first substrate100 and the second substrate 200. Also, the display device furtherincludes the sealing member 300 disposed between the first substrate 100and the second substrate 200.

The first substrate 100 supports various components to be formed on thefirst substrate 100. The first substrate 100 is made of an insulatingmaterial. For example, the first substrate 100 includes a rigid orflexible substrate, but the present disclosure is not limited thereto.That is, the first substrate 100 may be formed of various materials.

The second substrate 200 may be implemented with the same material asthe first substrate 100.

Hereinafter, the display device according to the first embodiment of thepresent disclosure will be described generally in the stacking order ofits layers. For convenience, the first substrate 100 will be firstdescribed, and the second substrate 200 will be next described.

A buffer layer 110 is provided on the first substrate 100. The bufferlayer 110 prevents impurities from the first substrate 100 fromdiffusing into upper layers, and improves the flatness of the firstsubstrate 100. The buffer layer 110 may be omitted according to materialand process conditions of the first substrate 100.

An active pattern 120 is provided on the buffer layer 110. The activepattern 120 is formed of a semiconductor material. The active pattern120 includes a source region SP, a drain region DP, and a channel regionCP provided between the source region SP and the drain region DP. Theactive pattern 120 may be doped or undoped silicon, e.g., poly-siliconor amorphous silicon. The active pattern 120 may be a semiconductorpattern made of an oxide semiconductor, etc.

A gate insulating layer 125 is provided over the active pattern 120.

A gate electrode 130 is provided on the gate insulating layer 125. Thegate electrode 130 may be formed to cover a region corresponding to thechannel region CP of the active pattern 120.

An interlayer insulating layer 135 covering the gate electrode 130 isprovided over the gate electrode 130. The interlayer insulating layer135 may include the same material as the gate insulating layer 125. Theinterlayer insulating layer 135 may insulate the gate electrode 130 froma source electrode 140 and a drain electrode 150, which will bedescribed later.

Openings passing through the gate insulating layer 125 and theinterlayer insulating layer 135 expose the source and drain regions SPand DP of the active pattern 120 therethrough.

The source electrode 140 and the drain electrode 150 are provided on theinterlayer insulating layer 135. The source electrode 140 and the drainelectrode 150 are electrically connected to the respective source anddrain regions SP and DP by the openings formed in the gate insulatinglayer 125 and the interlayer insulating layer 135.

Here, the active pattern 120, the gate electrode 130, the sourceelectrode 140, and the drain electrode 150 constitute a thin filmtransistor TFT. The structure of the thin film transistor TFT is notnecessarily limited thereto however, and the thin film transistor TFTmay have various configurations. For example, the thin film transistorTFT may be formed as a top gate type TFT, or may be formed with a bottomgate structure in which the gate electrode 130 is disposed under theactive pattern 120.

A protective layer 145 is provided over the source electrode 140 and thedrain electrode 150. The protective layer 145 covers the thin filmtransistor TFT, and may include at least one layer. Also, the protectivelayer 145 planarizes a surface of the lower structure. The protectivelayer 145 includes a contact hole through which a portion of the drainelectrode 150 is exposed.

An organic light emitting element OLED is provided on the protectivelayer 145. The organic light emitting element OLED may include a firstelectrode 160 electrically connected to the drain electrode 150, a lightemitting layer 170 disposed on the first electrode 160, and a secondelectrode 180 disposed on the light emitting layer 170.

One of the first and second electrodes 160 and 180 may be an anodeelectrode, and the other of the first and second electrodes 160 and 180may be a cathode electrode. For example, the first electrode 160 may bean anode electrode, and the second electrode 180 may be a cathodeelectrode. Here, the first electrode 160 may be used as a cathodeelectrode. However, in the following embodiment, a case where the firstelectrode 160 is an anode electrode will be described as an example.

The first electrode 160 may be formed of a material having a high workfunction. In the figures, when images are to be provided toward thelower direction of the first substrate 100, the first electrode 160 maybe formed of a transparent conductive layer such as indium tin oxide(ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or indium tin zincoxide (ITZO). In these figures, when images are to be provided towardthe upper direction of the first substrate 100, the first electrode 160may be formed of a metallic reflective layer such as Ag, Mg, Al, Pt, Pd,Au, Ni, Nd, Ir, or Cr, and a transparent conductive layer such as ITO,IZO, ZnO, or ITZO.

The first electrode 160 may be electrically connected to the drainelectrode 150 through the contact hole of the protective layer 145.

A pixel defining layer 155 that defines a pixel region of each pixel PXLmay be provided on the first electrodes 160. The pixel defining layer155 exposes a top or upper surface of the first electrode 160, andprotrudes from the first substrate 100 along the circumference of thepixel PXL.

The light emitting layer 170 is provided on the portion of the firstelectrode 160 exposed by the pixel defining layer 155, and the secondelectrode 180 is provided on the light emitting layer 170.

An encapsulation layer 400 for covering the second electrode 180 isprovided over the second electrode 180. The encapsulation layer 400 maybe formed as a single layer. However, the encapsulation layer 400 mayalso be formed with multiple layers.

The second substrate 200 will now be described, generally in itsstacking order.

The second substrate 200 may be made of the same material as the firstsubstrate 100, but the present disclosure is not limited thereto.

A touch sensing part 210 is provided on the second substrate 200. Thetouch sensing part 210 may include sensing electrodes, and connectionlines connected to the sensing electrodes. The sensing electrodes may bearranged on the second substrate 200, in a region corresponding to thefirst region 100 a of the first substrate 100 and part of the secondregion 100 b of the first substrate 100. The connection lines may bearranged on the second substrate 200, in a region corresponding to thesecond region 100 b and/or the third region 100 c of the first substrate100.

A protective film 220 is provided over the touch sensing part 210. Theprotective film 220 functions to protect the touch sensing part 210 fromthe outside. The protective film 220 may be configured in the form of afilm in which one or more layers of an inorganic material are coated onan organic material, but the present disclosure is not limited thereto.

Referring back to FIGS. 1, 3, and 4, the first substrate 100 includingthe above-described components may be divided into the first region 100a that is a display region, the second region 100 b disposed at theoutside of the first region 100 a, and the third region 100 csurrounding the second region 100 b, the third region 100 c having thesealing member 300 disposed therein.

A plurality of pixels PXL may be provided in the first region 100 a ofthe first substrate 100. Each of the plurality of pixels PXL may includeat least one thin film transistor TFT and an organic light emittingelement OLED connected to the thin film transistor TFT as describedabove. Here, the second electrode 180 of the organic light emittingelement OLED may be disposed to extend from the first region 100 a ofthe first substrate 100 to a portion of the second region 100 b of thefirst substrate 100.

A circuit part 190 for driving the thin film transistor TFT and theorganic light emitting element OLED may be disposed in the second region100 b of the first substrate 100. The circuit part 190 may includevarious circuit patterns, e.g., a power line, an anti-electrostaticpattern, and the like. The circuit part 190, as shown in in FIG. 4, maybe disposed over both the second region 100 b and the third region 100 con the first substrate 100, but the present disclosure is not limitedthereto. For example, the circuit part 190 may be disposed in only thesecond region 100 b. In addition, the circuit part 190 may be disposedin only the third region 100 c.

The sealing member 300 is provided in the third region 100 c of thefirst substrate 100. The sealing member 300 joins the first substrate100 and the second substrate 200, to seal the organic light emittingelement OLED disposed in the first region 100 a. The sealing member 300is heated by irradiation of a laser beam, to seal the organic lightemitting element OLED through a subsequent sealing process in which thesealing member 300 is cured. As an example, the sealing member 300 mayinclude a glass frit, etc.

The touch sensing part 210 may be disposed on the second substrate 200,over the first and second regions 100 a and 100 b. When viewed planview, one end portion of the touch sensing part 210 may overlap one endportion of the sealing member 300 in a region corresponding to thesecond region 100 b, but the present disclosure is not limited thereto.For example, the one end portion of the touch sensing part 210 may bespaced apart from the one end portion of the sealing member 300. In anembodiment of the present disclosure, the touch sensing part 210 and thesealing member 300 may be spaced apart from each other in a regioncorresponding to the second region 100 b of the first substrate 100.

The second electrode 180 may be disposed over the first and secondregions 100 a and 100 b of the first substrate 100. The second electrode180 and the touch sensing part 210 may partially overlap each other inthe second region 100 b of the first substrate 100. When viewed in planview, one end portion of the touch sensing part 210 may extend past thesecond electrode 180 toward the sealing member 300, in a regioncorresponding to the second region 100 b of the first substrate 100.Therefore, part of the touch sensing part 210 does not overlap thesecond electrode 180 in the second region 100 b, but instead extendsbeyond it. The touch sensing part 210 and the second electrode 180 maybe designed such that the width d of the non-overlapping portion is 80μm or more.

Meanwhile, the sealing member 300 is formed and cured by irradiation ofa laser beam. As described above, the one end portion of the touchsensing part 210 extends further toward the sealing member 300 than theone end portion of the second electrode 180 in the region correspondingto the second region 100 b of the first substrate 100, so that it ispossible to prevent the second electrode 180 from being exposed to thelaser beam when the sealing member 300 is cured. Accordingly, it ispossible to prevent the laser beam from propagating to the secondelectrode 180, thereby preventing deterioration of the light emittinglayer 170 disposed under the second electrode 180.

As a result, in the display device according to the first embodiment ofthe present disclosure, it is possible to prevent the light emittinglayer 170 from being deteriorated by the laser beam used in the curingof the sealing member 300, thereby reducing or minimizing defects in theorganic light emitting element OLED.

In the display device according to the first embodiment of the presentdisclosure, the touch sensing part may be provided as below.

FIG. 5 is a plan view illustrating the touch sensing part of the displaydevice of FIG. 3.

Referring to FIGS. 3 and 5, the touch sensing part 210 is provided onthe second substrate 200. The touch sensing part 210 may include sensingelectrodes 210 a arranged in a sensing region SA, and connection lines210 b arranged in a peripheral region PA surrounding the edge of thesensing region SA. Here, the sensing region SA may correspond to thefirst region 100 a of the first substrate 100. The peripheral region PAmay correspond to the second and third regions 100 b and 100 c of thefirst substrate 100.

The sensing electrodes 210 a may include a plurality of sensingelectrode rows arranged to be connected in a first direction DR1, and aplurality of sensing electrode columns arranged to be connected in asecond direction DR2 intersecting the first direction DR1. The material,shape, and arrangement structure of the sensing electrodes 210 a mayhave various modified embodiments according to touch sensing schemes ofthe display device, but the present disclosure is not limited thereto.That is, sensing electrodes 210 a of any materials, sizes, shapes, andarrangements are contemplated.

The connection lines 210 b connect the sensing electrodes 210 a to adriving circuit for driving the touch sensing part 210. The drivingcircuit may be an external component. The driving circuit may include aposition detecting circuit. The connection lines 210 b may transmit asensing input signal from the driving circuit to the sensing electrodes210 a, and/or may transmit a sensing input signal from the sensingelectrodes 210 a to the driving circuit. The connection lines 210 b maybe connected to a pad part 230 to be electrically connected to thedriving circuit.

In the display device according to the first embodiment of the presentdisclosure, the pixels may be provided in the following form.

FIG. 6 is a circuit diagram corresponding to a pixel of the displaydevice shown in FIG. 1. FIG. 7 is a plan view corresponding to the pixelof FIG. 6. FIG. 8 is a sectional view taken along line III-III′ of FIG.7.

Referring to FIGS. 1 and 6 to 8, the display device includes a firstsubstrate 100, a line part, and a pixel PXL. The pixel PXL displays animage, and may be provided in plural numbers as described above to bearranged in a matrix form. However, in FIGS. 6 and 7, only one pixel PXLhas been illustrated for convenience of description. Here, it has beenillustrated that the pixel PXL has a rectangular shape. However, thepresent disclosure is not limited thereto, and the pixel PXL may beconfigured in various shapes.

The pixel PXL is provided on the first substrate 100.

The line part provides a signal to the pixel PXL, and includes a scanline SL, a data line DL, and a driving voltage line ELVDD.

The scan line SL extends in one direction. The data line DL extends inanother direction intersecting the scan line SL. The driving voltageline ELVDD may extend in substantially the same direction as one of thescan line SL and the data line DL, e.g., the data line DL. In each pixelPXL, scan line SL transmits a scan signal to a thin film transistor, thedata line DL transmits a data signal to the thin film transistor, andthe driving voltage line ELVDD provides a driving voltage to the thinfilm transistor.

Each pixel PXL includes the thin film transistor connected to the linepart, an organic light emitting element OLED connected to the thin filmtransistor, and a capacitor Cst.

In more detail, each pixel PXL may include a driving thin filmtransistor TFT2 for controlling the organic light emitting element OLED,and a switching thin film transistor TFT1 for switching the driving thinfilm transistor TFT2. In an embodiment of the present disclosure, it isillustrated that one pixel PXL includes two thin film transistors TFT1and TFT2 and one capacitor Cst, but the present disclosure is notlimited thereto.

The switching thin film transistor TFT1 includes a first gate electrode130 a, a first source electrode 140 a, and a first drain electrode 150a. The first gate electrode 130 a is connected to the scan line SL, andthe first source electrode 140 a is connected to the data line DL. Thefirst drain electrode 150 a is connected to a gate electrode (i.e., asecond gate electrode 130 b) of the driving thin film transistor TFT2.The switching thin film transistor TFT1 transmits a data signal from thedata line DL to the driving thin film transistor TFT2 in response to ascan signal applied to the scan line SL.

The driving thin film transistor TFT2 includes the second gate electrode130 b, a second source electrode 140 b, and a second drain electrode 150b. The second gate electrode 130 b is connected to the switching thinfilm transistor TFT1, and the second source electrode 140 b is connectedto the driving voltage line ELVDD. The second drain electrode 150 b isconnected to the organic light emitting element OLED.

The switching thin film transistor TFT1 and the driving thin filmtransistor TFT2 respectively include a first active pattern 120 a and asecond active pattern 120 b, which are formed of a semiconductormaterial. Each of the first active pattern 120 a and the second activepattern 120 b includes a source region SP, a drain region DP, and achannel region CP. The first active pattern 120 a and the second activepattern 120 b may be semiconductor patterns made of poly-silicon,amorphous silicon, oxide semiconductor, etc.

The organic light emitting element OLED includes a light emitting layer170, and a first electrode 160 and a second electrode 180 which areopposite to each other with the light emitting layer 170 interposedtherebetween.

The first electrode 160 is connected to the second drain electrode 150 bof the driving thin film transistor TFT2. The first electrode 160 servesas an anode electrode and is an electrode for hole injection. The firstelectrode 160 may include a material having a high work function.

The light emitting layer 170 emits light based on an output signal ofthe driving thin film transistor TFT2, so that an image is displayed asthe light is emitted or not emitted. Here, the light emitted from thelight emitting layer 170 may be changed depending on the material of thelight emitting layer 170. The light may be colored light or white light.

The second electrode 180 may include a material having a lower workfunction than the first electrode 160. For example, the second electrode180 may include at least one of molybdenum (Mo), tungsten (W), silver(Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold(Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium(Li), calcium (Ca), and alloys thereof.

The capacitor Cst is connected between the second gate electrode 130 band the second source electrode 140 b of the driving thin filmtransistor TFT2. The capacitor Cst includes a first capacitor electrodeCE1 connected to the first drain electrode 150 a of the switching thinfilm transistor TFT1, and a second capacitor electrode CE2 extendingfrom the driving voltage line ELVDD and located on the first capacitorelectrode CE1. The capacitor Cst charges and maintains a data signalinput to the second gate electrode 130 b of the driving thin filmtransistor TFT2.

A protective layer 145 is formed over the switching thin film transistorTFT1 and the driving thin film transistor TFT2. The protective layer 145covers the switching thin film transistor TFT1 and the driving thin filmtransistor TFT2, and may include at least one layer. The protectivelayer 145 includes a contact hole through which a portion of the seconddrain electrode 150 b is exposed.

FIG. 9 is a graph illustrating changes in temperature of sealingmembers, second electrodes, and pixels due to irradiation of a laserbeam, for both a conventional display device and a display deviceaccording to the first embodiment of the present disclosure. FIG. 10 isan enlarged graph of a portion corresponding to P2 of FIG. 9.

In the graphs of FIGS. 9 and 10, the X-axis respectively represents adistance between a sealing member and a second electrode and a distancebetween the sealing member and a pixel. In the graph, the Y-axisrepresents values obtained by measuring surface temperatures of thesealing member, the second electrode, and the pixel resulting fromirradiation of a laser beam onto the sealing member. The sealing memberonto which the laser beam is directly irradiated may be located at thecenter of the X-axis of the graph. In addition, the left side of theX-axis of the graph represents a distance between the sealing member andthe second electrode, and the right side of the X-axis of the graphrepresents a distance between the sealing member and the pixel.

In FIG. 10, the portion designated as Comparison Group representsmeasurements taken from a conventional display device, and the portiondesignated as Experimental Group 1 represents measurement values takenfrom a display device according to the first embodiment of the presentdisclosure. Also, in FIG. 10, the portion designated as ExperimentalGroup 2 represents measurement values taken from a display device havingthe second electrode formed to have a thicker thickness than the secondelectrode included in the display device of Experimental Group 1.

It can be seen that, when the laser beam is irradiated onto the sealingmember, the surface temperature of the second electrode decreases as thedistance between the sealing member and the second electrode increases.In addition, it can be seen that, when the laser beam is irradiated ontothe sealing member, the surface temperature of the pixel decreases asthe distance between the sealing member and the pixel increases.

In each of Experimental Groups 1 and 2, it can be seen that the surfacetemperature of the second electrode increases as compared with theComparison Group. This is because the display device of ExperimentalGroup 1 and the display device of Experimental Group 2 are configured tominimize dead spaces, so that the distance between the sealing memberand the second electrode is narrow as compared with the ComparisonGroup.

Meanwhile, the light emitting layer of the organic light emittingelement included in the display device may be degraded and damaged at atemperature of about 300° C.

In each of the Comparison Group, Experimental Group 1, and ExperimentalGroup 2, as the second electrode comes close to the sealing member, thesurface temperature of the second electrode increases due to the laserbeam being irradiated onto the sealing member. However, the surfacetemperature of the second electrode does not reach the temperature(about 300° C.) at which the light emitting layer is damaged.

As described above, it has been observed that the surface temperaturesof all of the second electrodes of the Comparison Group, ExperimentalGroup 1, and Experimental Group 2 increase due to the laser beam beingirradiated onto the sealing member in the curing of the sealing member.However, it has been observed that the surface temperature of the secondelectrode included in each of the Comparison Group, Experimental Group1, and Experimental Group 2 does not increase to a temperature highenough to damage the light emitting layer disposed under the secondelectrode.

Consequently, in the display device according to the first embodiment ofthe present disclosure, the touch sensing part prevents the secondelectrode from being exposed to the laser beam, even though dead spaceis reduced by extending the second electrode in the direction toward thesealing member. Accordingly, it is possible to prevent degradation ofthe light emitting layer.

FIGS. 11 to 14 are sectional views sequentially illustrating afabrication method for the display device of FIG. 4.

Referring to FIGS. 4 and 11, a thin film transistor TFT and an organiclight emitting element OLED connected to the thin film transistor TFTare formed in a first region 100 a of a first substrate 100. Inaddition, a circuit part 190 is formed in a second region 100 b of thefirst substrate 100. Here, the circuit part 190 may be provided on thefirst substrate 100, extending from the second region 100 b to a portionof a third region 100 c of the first substrate 100.

Referring to FIG. 12, an encapsulation layer 400 for covering the thinfilm transistor TFT and the organic light emitting element OLED isformed over the first and second regions 100 a and 100 b of the firstsubstrate 100.

In addition, a sealing member 300 is formed in the third region 100 c ofthe first substrate 100. The sealing member 300 joins the firstsubstrate 100 to a second substrate provided in a subsequent process, toseal the organic light emitting element OLED inside the first region 100a. The sealing member 300 is heated by irradiation of a laser beam, toseal the organic light emitting element OLED through a subsequentsealing process in which the sealing member 300 is cured. For example,the sealing member 300 may include a glass frit, etc.

Referring to FIG. 13, a second substrate 200 is prepared. The secondsubstrate 200 may include a material substantially identical or similarto that of the first substrate (100 of FIG. 12). The second substrate200 may serve as a sealing substrate for sealing the organic lightemitting element (OLED of FIG. 12) disposed on the first substrate 100.

After that, a touch sensing part 210 is formed on the second substrate200. The touch sensing part 210 may be disposed on the second substrate200 to extend from the second region 100 b to the first region 100 a ofthe first substrate 100.

Subsequently, a protective film 220 is formed over the touch sensingpart 210.

The second substrate 200 is then disposed to be opposite to the firstsubstrate 100, and a laser beam is irradiated onto the sealing member300, so that the first and second substrates 100 and 200 can be joinedtogether as shown in FIG. 14.

FIG. 15 is a sectional view illustrating a display device according to asecond embodiment of the present disclosure. In the display deviceaccording to the second embodiment of the present disclosure,differences from the display device according to the already-describedembodiments will be mainly described, to avoid redundancy. Portions notparticularly described in the second embodiment of the presentdisclosure follow those of the display device according to theabove-described embodiment. Identical reference numerals designateidentical components, and similar reference numerals designate similarcomponents.

Referring to FIG. 15, the display device according to the secondembodiment of the present disclosure includes a first substrate 100 anda second substrate 200, which are opposite to each other. Also, thedisplay device further includes a sealing member 300 disposed betweenthe first and second substrates 100 and 200.

Similar to previous embodiments, the first substrate 100 may be dividedinto a first region 100 a that is a display region, a second region 100b disposed at the outside of the first region 100 a, and a third region100 c surrounding the second region 100 b, the third region 100 c havingthe sealing member 300 disposed therein.

At least one thin film transistor TFT and an organic light emittingelement OLED connected to the thin film transistor TFT may be disposedin the first region 100 a of the first substrate 100.

The organic light emitting element OLED may include a first electrode160 electrically connected to the thin film transistor TFT, a lightemitting layer 170 disposed on the first electrode 160, and a secondelectrode 180′ disposed on the light emitting layer 170.

The second electrode 180′ may be disposed to extend from the first area100 a to the second area 100 b of the first substrate 100. Specifically,the second electrode 180′ may extend from the first area 100 a to thesecond area 100 b to come close to one end portion of the sealing member300 when viewed in plan view. Here, the second electrode 180′ mayinclude an opaque conductive material having a lower work function thanthe first electrode 160. Particularly, the second electrode 180′ may bemade of a thick opaque conductive material having at least apredetermined thickness, to facilitate the movement of electrons to thelight emitting layer 170.

The second substrate 200 includes a touch sensing part 210′ thatrecognizes a touch event of the display device, and a protective film220 that covers the touch sensing part 210′.

The touch sensing part 210′ may include sensing electrodes andconnection lines connected to the sensing electrodes. Here, the sensingelectrodes may be made of a transparent conductive material. Thetransparent conductive material may include indium tin oxide (ITO),indium zinc oxide (IZO), antimony zinc oxide (AZO), indium tin zincoxide (ITZO), zinc oxide (ZnO), tin oxide (SnO₂), carbon nano tube,graphene, and the like. The sensing electrodes may be formed in a singlelayer or multiple layers. In this case, the sensing electrodes mayinclude a multi-layered structure in which two or more materials fromamong the above-described materials are stacked.

The touch sensing part 210′ may be disposed on the second substrate 200,over a region corresponding to the first and second regions 100 a and100 b of the first substrate 100. When viewed in plan view, the touchsensing part 210′ may be disposed in a region corresponding to thesecond region 100 b of the first substrate 100 such that one end portionof the touch sensing part 210′ is located inward of one end portion thesealing member 300.

When viewed in plan view, one end portion of the second electrode 180′may be disposed outward of the one end portion of the touch sensing part210′ in the second region 100 b of the first substrate 100. Therefore, anon-overlapping portion at which the second electrode 180′ and the touchsensing part 210′ do not overlap with each other may be provided in theregion corresponding to the second region 100 b of the first substrate100. That is, the second electrode 180′ and the touch sensing part 210′may only partially overlap each other in the region corresponding to thesecond region 100 b of the first substrate 100.

Meanwhile, the sealing member 300 is formed as it is cured byirradiation of a laser beam. As described above, the one end portion ofthe second electrode 180′ extends closer to the sealing member 300 thanthe one end portion of the touch sensing part 210′, and therefore, thesecond electrode 180′ may be exposed to the laser beam when the sealingmember 300 is cured. When the laser beam is irradiated onto the secondelectrode 180′, the opaque material of the second electrode 180′ mayreflect the laser beam up toward the touch sensing part 210′. The touchsensing part 210′, made of transparent conductive material, may allowthe laser beam reflected by the second electrode 180′ to be transmittedto the outside. Thus, it is possible to prevent the laser beam frombeing again incident onto the second electrode 180′. Accordingly, it ispossible to prevent degradation of the light emitting layer 170 disposedunder the second electrode 180′ in the first region 100 a of the firstsubstrate 100.

Consequently, in the display device according to the second embodimentof the present disclosure, it is possible to prevent degradation of thelight emitting layer 170 due to the laser beam used in the curing of thesealing member 300, thereby minimizing defects in the organic lightemitting element OLED.

FIG. 16 is a sectional view illustrating a display device according to athird embodiment of the present disclosure. In the display deviceaccording to the third embodiment of the present disclosure, differencesfrom the display devices of previous embodiments will be mainlydescribed, to avoid redundancy. Portions not particularly described inthe third embodiment of the present disclosure follow those of thedisplay devices according to the above-described embodiments. Identicalreference numerals designate identical components, and similar referencenumerals designate similar components.

Referring to FIG. 16, the display device according to the thirdembodiment of the present disclosure includes a first substrate 100 anda second substrate 200, which are opposite to each other. Also, thedisplay device further includes a sealing member 300 disposed betweenthe first and second substrates 100 and 200.

The first substrate 100 may be divided into a first region 100 a that isa display region, a second region 100 b disposed at the outside of thefirst region 100 a, and a third region 100 c surrounding the secondregion 100 b, the third region 100 c having the sealing member 300disposed therein.

At least one thin film transistor TFT and an organic light emittingelement OLED connected to the thin film transistor TFT may be disposedin the first region 100 a of the first substrate 100.

A second electrode 180″ included in the organic light emitting elementOLED may be disposed to extend from the first region 100 a to the thirdregion 100 c of the first substrate 100. Specifically, the secondelectrode 180″ may extend from the first region 100 a to the thirdregion 100 c to overlap the sealing member 300 when viewed in plan view.

The second substrate 200 includes a touch sensing part 210′ thatrecognizes a touch event of the display device, and a protective film220 that covers the touch sensing part 210′.

The touch sensing part 210′ may be disposed on the second substrate 200,over a region corresponding to the first and second regions 100 a and100 b of the first substrate 100. When viewed in plan view, the touchsensing part 210′ may be disposed in a region corresponding to thesecond region 100 b of the first substrate 100 such that one end portionof the touch sensing part 210′ is located inward of one end portion thesealing member 300.

When viewed in plan view, one end portion of the second electrode 180′may be disposed outward of the one end portion of the touch sensing part210′ in the second region 100 b of the first substrate 100. Therefore, anon-overlapping portion at which the second electrode 180″ and the touchsensing part 210′ do not overlap with each other may be provided in theregion corresponding to the second region 100 b of the first substrate100. That is, the second electrode 180″ and the touch sensing part 210′may only partially overlap each other in the region corresponding to thesecond region 100 b of the first substrate 100, with the secondelectrode 180″ extending beyond the touch sensing part 210′ in planview.

Meanwhile, the sealing member 300 is formed as it is cured byirradiation of a laser beam.

As described above, the one end portion of the second electrode 180′extends closer to the sealing member 300 than the one end portion of thetouch sensing part 210′ in the second region 100 b of the firstsubstrate 100, and therefore, the second electrode 180″ may be exposedto the laser beam when the sealing member 300 is cured.

When the laser beam is irradiated onto the second electrode 180″, thesecond electrode 180″, being opaque, may reflect the laser beam backtoward the touch sensing part 210′. The touch sensing part 210′, beingtransparent, may allow the laser beam reflected by the second electrode180″ to be transmitted to the outside. Thus, it is possible to preventthe laser beam from being again incident to the second electrode 180″.Accordingly, it is possible to prevent degradation of the light emittinglayer 170 disposed under the second electrode 180″ in the first region100 a of the first substrate 100.

According to the present disclosure, it is possible to provide a displaydevice that minimizes a defect of a display device.

According to the present disclosure, it is possible to provide a methodfor fabricating the display device.

Example embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of ordinary skill in the art asof the filing of the present application, features, characteristics,and/or elements described in connection with a particular embodiment maybe used singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwisespecifically indicated. Accordingly, it will be understood by those ofskill in the art that various changes in form and details may be madewithout departing from the spirit and scope of the present disclosure asset forth in the following claims. Various features of the abovedescribed and other embodiments can be mixed and matched in any manner,to produce further embodiments consistent with the invention.

What is claimed is:
 1. A display device comprising: a first substrateincluding a first region, a third region spaced apart from andsurrounding the first region, and a second region located between thefirst region and the third region; a second substrate opposite to thefirst substrate; a display element including a first electrode providedon the first substrate, a light emitting layer provided on the firstelectrode, and a second electrode provided on the light emitting layer;a touch sensing part disposed on the second substrate; and a sealingmember provided on the third region of the first substrate, the sealingmember joining the first substrate and the second substrate, wherein thesecond electrode overlaps with the touch sensing part when viewed on aplane, and an end of the second electrode is spaced apart from an end ofthe touch sensing part at a certain distance in the direction of thesealing member in the second region, wherein the second electrode isdisposed on the first region and the second region, and does not overlapthe sealing member, wherein the end of the second electrode is disposedcloser to the sealing member than the end of the touch sensing part. 2.A display device comprising: a first substrate including a first region,a third region spaced apart from and surrounding the first region, and asecond region located between the first region and the third region; asecond substrate opposite to the first substrate; a display elementincluding a first electrode provided on the first substrate, a lightemitting layer provided on the first electrode, and a second electrodeprovided on the light emitting layer; a touch sensing part disposed onthe second substrate; and a sealing member provided on the third regionof the first substrate, the sealing member joining the first substrateand the second substrate, wherein the second electrode overlaps with thetouch sensing part when viewed on a plane, and an end of the secondelectrode is spaced apart from an end of the touch sensing part at acertain distance in the direction of the sealing member in the secondregion, wherein the second electrode is disposed at portions of thefirst region, the second region, and the third region, and partiallyoverlaps with the sealing member in the third region when viewed on aplane.
 3. The display device of claim 2, wherein the end of the secondelectrode extends to a lower surface of the sealing member.
 4. A displaydevice comprising: a first substrate including a first region in whichan image is displayed, a second region provided at the periphery of thefirst region, and a third region provided at the periphery of the secondregion; a second substrate provided on the first substrate; a pluralityof pixels displaying the image, the plurality of pixels each includingat least one thin film transistor and a light emitting device connectedto the thin film transistor; a touch sensing part provided on the secondsubstrate; and a sealing member provided in the third region, thesealing member joining the first substrate and the second substrate,wherein the light emitting device includes a first electrode provided onthe first substrate, a light emitting layer provided on the firstelectrode, and a second electrode provided on the light emitting layer,wherein the second electrode overlaps with the touch sensing part whenviewed on a plane, and an end of the second electrode is spaced apartfrom an end of the touch sensing part at a certain distance in thedirection of the sealing member in the second region, wherein the end ofthe second electrode is disposed closer to the sealing member than theend of the touch sensing part.
 5. The display device of claim 4, whereinthe second electrode is disposed at portions of the first region, thesecond region, and the third region, and partially overlaps with thesealing member in the third region when viewed on a plane.
 6. Thedisplay device of claim 5, wherein the end of the second electrodeextends to a lower surface of the sealing member.